Since the organic electroluminescent (hereafter, electroluminescent may be abbreviated as EL) element comprising an organic light emitting layer interposed between a pair of electrodes for applying voltage between the electrodes for emitting a light are advantageous for having: high visibility owing to self color development, excellent impact resistance for being an all solid element unlike the liquid crystal elements, high response speed, little influence by the temperature change, wide view angle, and the like so that utilization as a light emitting element in a display device attracts attention.
In such an organic EL element, in the case of producing a transparent panel having a first electrode and a second electrode disposed on both sides of an organic light emitting layer as transparent electrodes, a problem of display irregularity has been brought about due to high resistance of the second electrode.
Then, for lowering the resistance of the second electrode, a method of forming an auxiliary electrode for the second electrode on a glass substrate for connecting the same by a through hole has been proposed (see Patent Literature 1). However, due to increase of producing steps, the method involves a problem of complication. On the other hand, a method of forming an auxiliary electrode directly on a second electrode has been proposed (see Patent Literature 2). However, since the auxiliary electrode is formed between the light emitting elements disposed according to a matrix arrangement in this method, a problem is involved in that alignment adjustment is difficult.